During the spin cycle of a washing machine, water is removed from wet clothes centrifugally by spinning the clothes at high speed in a spin basket. In order to reduce the possibility of injury to the user, the user must be prevented from having access to the spin basket while the spin basket is in motion.
One way of protecting the user from access to the rotating spin basket uses an electrically locking latch for the washing machine lid. The latch holds and locks the lid in a closed position for the duration of the spin cycle and for a period after the spin cycle necessary for the spin basket to coast to a stop. This locking latch may be operated by a thermoelectric element such as a bimetallic strip or wax motor. Preferably, however, a fast acting solenoid may be used for the locking mechanism to permit rapid access to the clothes when the spin basket has stopped. Often, to save electrical power, a solenoid may be a bi-stable solenoid receiving a first pulse of electricity to lock the lid and a second pulse of electricity to unlock the lid.
In order to prevent defeat of the lock, it is known to put a lid switch in series with the bi-stable solenoid to prevent the locking action when the lid is open. This lid switch may be accompanied with a “lock switch” indicating that the bolt of the lock is engaged with a door striker. The lock switch is then placed in series with the washing machine motor to prevent activation of the spin cycle when the lid is not properly locked. Together the lid closure switch and the lid lock switch provide some assurance that the lid is properly closed and locked before power is applied to the washing machine mechanism.